Track surveying method

ABSTRACT

A surveying vehicle is continuously moved on and along a track, the track is subjected to mechanical forces from the continuously moving vehicle, and the change in the track produced by the mechanical forces is measured. Signals corresponding to the measured changes indicate track conditions at successive track points where the mechanical forces have been exerted.

United States Patent Plasser et al. Feb. 22, 1972 [54] TRACK SURVEYINGMETHOD [56] References Cited [72] Inventors: Franz Plasser; JosefTheurer, both of UNITED STATES PATENTS Mannesgasse 1010 Vienna;3,481,183 12/1969 Swift ..73/146 Schubert, Lainzerstrasse Vienna2,966,123 12/1960 Talboys ..104/s -1 OfAusma 3,240,161 3/1966 Beleau etal. ...104/8 22 Filed: Apr. 7 1969 3,334,592 8/1967 Plasser Cl al 104/8[21 Appl. No.: 813,854 Primary Examiner-Arthur L. La Point AssistantExaminer-Richard A. Bertsch Attorney-Kurt Kelman [30] ForeignApplication Priority Data Apr. 9, 1968 Austria ..A3507/68 [571 ABSTRACTA surveying vehicle is continuously moved on and along a [52] U.S.C|i..73/l46, 104/8 track, the track is subjected to mechanical forces fromthe [S1] lnt.Cl ..E0lb 35/00 continuously moving vehicle, and the changein the track [58] Field of Search ..33/60, 146; 104/7, 7 B, 8, producedby the mechanical forces is measured. Signals corresponding to themeasured changes indicate track conditions at successive track pointswhere the mechanical forces have been exerted.

12 Claims, 10 Drawing Figures TRACK SURVEYING METHOD BACKGROUND OF THEINVENTION The present invention relates to a method for determiningphysical conditions of a railroad track by means of a vehiclecontinuously moving on and along the track in the direction of trackelongation.

Surveying cars are known to determine the grade, lining, gage,superelevation and skew of a track, as well as the condition of therails and rail fastenings, by means of sensors contacting the trackrails and indicating the position in relation to an elongated vehicleframe serving as reference. However, it is not possible with knownsystems to determine a characteristic value of the track condition.

BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates toa method for determining physical conditions of a railroad track bymeans of a vehicle continuously moving on and along the track in thedirection of track elongation.

Surveying cars are known to determine the grade, lining, gage,superelevation and skew of a track, as well as the condition of therails and rail fastenings, by means of sensors contacting the trackrails and indicating the position in relation to an elongated vehicleframe sewing as reference. However, it is not possible with knownsystems to determine a characteristic value of the track condition.

It it the primary object of this invention to produce a surveying systemwhich makes it possible to determine all essential characteristic valuesindicative of the physical condition of a track while continuouslymoving along the track without stopping at track points whose conditionsare to be determined.

This and other objects are accomplished in accordance with the inventionby continuously moving a surveying vehicle on and along the track in thedirection of track elongation, and subjecting the track to preferably aplurality of mechanical forces, loads or pressures from the continuouslymoving vehicle. The magnitudes of the changes in the track, such aschanges in the shape or position of the track, are measured, and themeasured values are used to indicate condition of the track. One or moremeasuring devices are used for measuring such changes in any suitablemanner.

The condition of a track or track part can be determined by the effect atest load or force applied to the track or track part has thereon. Forinstance, the stifi'ness of a track rail or the resilience or yield of aballast bed, as well as other characteristics of the track, may bedetermined by obtaining a value characteristic of the changes in theshape or position of the track under a controlled mechanical forceapplied thereto. This fact is used in the present invention in acontinuously advancing surveying operation along a track.

BRIEF DESCRIPTION OF DRAWING The above and other objects, advantages andfeatures of the present invention will be better understood by referenceto the following detailed description of certain now preferredembodiments of apparatus capable of carrying out the method of thisinvention, taken in conjunction with the accompanying schematic drawingwherein.

FIG. I is a top view of the running gears of one embodiment of anapparatus useful for the invention;

FIGS. 2 to 9 are side views of vehicles incorporating differentembodiments of the invention; and

FIG. 10 is a top view of the running gears of the vehicle of F IG. 9.

DETAILED DESCRIPTION The vehicle of FIG. 1 has three running gears I, 2and II with wheels running on rails G of a railroad track. An axle l0interconnects the two main running gears 1, ll and the intermediaterunning gear 2 is connected to the axle by means of hydraulic motors 2'which, upon operation, exert a predetermined, variable, horizontal forceor pressure upon a selected one of the track rails, i.e., laterally movethe track and thus change its shape or position. A suitable measuringdevice of any desired type (not shown) measures the thus produced trackchanges to produce a signal characteristic of local physical conditionsof the track, such as the ballast bed condition, the condition of thetrack ties, the condition of the rail fastening, etc. I

In this and all other embodiments of the invention, th means on thevehicle for subjecting the track to mechanical forces has the purpose ofchanging the track, particularly to change the shape or positionthereof, and signals indicating measured values of these changes areused to determine physical conditions of the track or track parts. Moreparticularly, different changes in the track produced by mechanicalforces of different magnitudes may be used to produce signalscharacteristic of certain track conditions and derived from a comparisonof the different forces.

FIGS. 2 and 3 illustrate track surveying vehicles with means forsubjecting the track G to mechanical forces of predetermined anddifferent sizes at points of the track spaced from each other in thedirection of track elongation. The vehicles are mounted on pairs ofswivel trucks.

In the embodiments of FIG. 2, loads 3' and 4' of different sizes exertdifferent vertical forces upon swivel trucks 3 and 4 of the vehicle,each truck having the :same number of axles, i.e., three. In theembodiment of FIG. 3, the swivel trucks 3a and 4la have differentnumbers of axles, i.e., the truck 3a has three axles and the truck 4ahas two axles. The loads 5 and 6 may be of the same size or of differentsizes, the vertical forces exerted thereby on the trucks beingdistributed over a different number of axles, thus producing a differentdownward pressure on the axles of the front and rear trucks.

In this manner, the track is simultaneously subjected to mechanicalforces at points spaced from each other in the direction of trackelongation, and as the vehicle shown in FIG. 3 moves continuously alongand on the track, it is subjected to successive mechanical forces ofdifferent size at the same point, the resultant characteristic signalsbeing measured and compared to determine physical conditions of thetrack.

The embodiment of FIG. 4 is substantially identical with that of FIG. 2,except that each swivel truck 3b, 4b has four axles so that the loads 5,6' are distributed thereover at successive track points simultaneously.

The embodiments of FIGS. 5 to 8 assure more accurate control of themechanical forces to which the track is subjected, thus producing morereliable signals characteristic of the measured changes andcorresponding conditions of the track. In these embodiments, a surveyingvehicle runs on track G on front and rear axles or running gears, and asatellite carriage is mounted on the vehicle and moves on the track withthe vehicle. Means is provided for exerting a predetermined force orpressure on the satellite carriage.

In the embodiment of FIG. 5, the vehicle A runs on axles 8 and carriessatellite carriage B intermediate the axles. The satellite carriage, inturn, has two axles 7 also running on Track G intermediate axles 8 ofvehicle A. A hydraulic motor 9 is mounted on the vehicle and connectedto the satellite carriage to exert thereon (and on its axles 7) acarefully controllable vertical pressure. Obviously, the hydraulic motormay be mounted for exerting a horizontal pressure on the satellitecarriage.

In the embodiment of FIG. 6, two satellite carriages B B are mounted onthe surveying vehicle A, each at the axles 8, 8 of the vehicle, with theaxles 7', 7' of the satellite carriages on either side of the vehicleaxles. This produces four successive track points at which a controlledand measurable mechanical force is exerted upon the track by thesatellite carriage axles.

The embodiment of FIG. 7 differs from that of FIG. 5 only in that theaxles 7", 7 of the satellite carriage B are arranged outside the vehicleaxles 8, 8, instead of therebetween, so that the satellite carriageaxles exert a force on the track at or near the two ends of the vehicle.

Further variation of the applied mechanical forces is possible with theembodiment of FIG. 8 wherein the downward force exerted by the axles 8',8' of the surveying vehicle A also differs. In the illustratedembodiment, this is accomplished by making the surveying vehicleasymmetric so that the one axle 8' carries a heavier load than the otheraxle 8. Of course, the same result would be accomplished by placingdifferent loads upon the respective axles, such as shown in FIG. 2, forexample. Additional, relatively small downward pressure is exerted uponthe track by satellite carriages B,, B mounted in the same manner asshown in FIG. 6.

The embodiment of FIGS. 9 and 10 differs from that of FIG. 6 in thespecial mounting of the satellite carriages B and B on the surveyingvehicle A, enabling the apparatus not only to subject the track tomechanical forces in a vertical and/or horizontal direction but also todetermine, measure and compare changes of position of the satellitecarriages in relation to each other and to the surveying vehicle, usingthe corresponding signals to measure the changes in the track shape orposition caused by the mechanical forces to which the track has beensubjected.

For instance, these signals may be produced by measuring angle in avertical plane and/or angle in a horizontal plane between linesextending in the direction of track elongation and constituted, forinstance, by rods on the satellite carriages, the angles being definedbetween associated lines of the two carriages, one line extending in adirection determined by the position of the one carriage B and the otherline extending in a direction determined by the position of the othercarriage B FIG. also shows that axles 7", 7" of the satellite carriagesmay be subjected to lateral forces K while the carriages themselvesserve as a reference or datum line in relation to which characteristicvalues may be measured. As shown in this figure, when the surveyingvehicle moves in a track curve, one of the wheels of the front axles 7',7 of the satellite carriages automatically is pressed with its rimagainst the head of the grade rail while the rear carriage axles 7", 7has an indeterminate position. Therefore, it is sufficient to limit thelateral force to the rear axles.

As is well known in track surveying, surfacing and lining operations, anadditional an preferably longer reference line may be established andmaintained independently of, and separately from, the satellitecarriages, such reference systems usually including a plurality ofmeasuring bogies at spaced points along the track elongation and areference line, such as a beam of electromagnetic radiation or tensionedwire, established between the measuring bogies.

As shown in FIG. 10, the satellite carriages have frames constituted bylinked rods which are freely movable in relation to each other so thatall wheels may engage the rails with their rims and thus follow thecourse of the track rails G even when the same are skew, for instance ina superelevated track section, such as a curve. Such satellite carriagesmay then be used to measure the twist in the track rails by using therelative position of the axles of each carriage and of the axles ofneighboring carriages. FIG. 10 shows the satellite carriages B, and Blaterally pressed by forces K against the grade rail whose position isto be surveyed, these carriages or parts thereof serving as reference inrelation to which, for instance by measuring angle B, the characteristicvalues are determined.

While not illustrated, the surveying vehicle may also carry means forproducing vibrations in at least one track rail, an means for measuringthe rail vibrations. Such measurements may be used to produce signalscharacteristic of certain track conditions. For instance, the vibrationproducing means may be an impact tool or a flattened wheel or pair ofwheels to produce successive impacts on the track rails as the vehiclemoves therealong. As is known, the vibrations may be measured byconventional electroacoustical vibration meters.

As will be appreciated, the schematically illustrated embodiments ofsurveying apparatus are merely illustrative of the concepts underlyingthe present invention and may be used to carry out the method accordingthereto in a great variety of ways. For instance, the mechanical forces,to which the track is subjected from the continuously moving surveyingvehicle, may be so controlled from track point to track point as to varyas a function of the physical conditions at each point to produce apredetermined, constant value of measured changes of these conditions,for instance changes in the shape or position of the track or track partwhich has been subjected to the mechanical force. The varying sizes ofthe mechanical forces give a signal characteristic of the localconditions of the track. On the other hand, the size of the mechanicalforces may be kept constant to produce varying values as a function ofthe measured changes of the track conditions, and the varying values ofthe measured changes give signals characteristic of the local conditionof the track.

It is particularly advantageous if the track is subjected to mechanicalforces of different sizes at points of the track spaced from each otherin the direction of track elongation as the surveying vehiclecontinuously moves on and along the track. The resultant track changes,i.e., reshaping or repositioning of the track, are measured and comparedto use the measured differences as a characteristic of a given trackcondition. Such continuously produced signals are particularly useful inan automated operation which permits the signals to be continuouslyreceived, recorded and evaluated, for instance in a computer.

Variations within this preferred method are possible. Thus, themechanical forces of different sizes may be successively exerted uponthe same track point. For instance, with the vehicle shown in FIG. 8,the different pressures of the front and rear vehicle axles will beexerted upon the same track point successively as the vehicle movesalong the track, the differences in the track shape or position beingmeasured at each axle, and then compared. In this case, the track issimultaneously subjected to mechanical forces of different sizes atspaced points. Thus, while the changed track condition produced by arelatively small mechanical force is measured at one point, the changedtrack condition produced by a larger mechanical force is simultaneouslymeasured at a point spaced therefrom.

In the illustrated embodiments, the mechanical forces are loads orpressures in a horizontal and/or vertical direction exerted directly orindirectly upon one or both track rails.

The type and the direction of the mechanical forces will depend on thecharacteristic of the track which is to be determined. For instance, thecondition of the rails and the ballast bed is determined by exertingvertical pressures on the track. The condition of the rail fasteningsand the track tie positions, which are largely determined by the ballastdensity at the ends of the ties, can be determined on the basis of trackshape or position changes produced by horizontal or lateral pressures onthe track. For instance, if the two track rails are pressed in oppositelateral directions at the same or at least about the same track point,the resultant changes in the shape or position of the track rails can beused to generate signals characteristic of the condition of the tieposition or the rail fastening at this point.

Similar results are produced if the mechanical force consists of railvibration-producing means, rather than vertical and/or horizontalpressure means, the resultant vibrations in the rail or rails beingpreferably measured electroacoustically for obtaining signalscharacteristic of track conditions, such as the condition of the railsand rail fastenings but also the position of the track ties and thecondition of the ballast bed.

The more types and/or sizes of mechanical forces are exerted upon thesame track point, the more accurate and clear will be the determinationof the track condition at this point obtained by the signals resultingfrom the measured changes in the track produced by these varying forces.A composite picture of the track condition may then the produced byfeeding these varying signals to punch cards or directly to a computerfor evaluation Each combination of signals produces a composite picturewhich tells the track maintenance expert the condition of the track andits parts at each track point, the accuracy of this picture dependingprimarily on the number of measured values at each point. This shows theimportance and considerable advantage of subjecting each track pointsuccessively to different mechanical stresses, particularly stresses ofdifferent magnitudes.

We claim:

l. A method of determining the physical condition of a track, comprisingthe steps of l. continuously moving a vehicle on and along the track inthe direction of the track elongation;

2. subjecting the track to substantially constant mechanical forces ofdifierent magnitude from the continuously moving vehicle at points ofthe track spaced from each other in the direction of track elongation,the mechanical forces being sufficient to change the physical conditionof the track at the points of application only while the forces areapplied thereto;

3. measuring the changes in the track condition produced at said pointsby the different mechanical forces; and

4. determining the differences in the values of the measured changes.

2. The method of claim 1, wherein the track is simultaneously subjectedto said mechanical forces at said points.

3. A method of determining the physical condition of a track, comprisingthe steps of l. continuously moving a vehicle on and along the track inthe direction of the track elongation;

2. subjecting the track to successive substantially constant mechanicalforces of different magnitudes at the same point from the continuouslymoving vehicle, the mechanical forces being sufficient to change thephysical condition of the track at the points of application only whilethe forces are applied thereto; and

3. measuring the changes in the track condition produced at each of saidpoints by said mechanical forces to indicate the condition of the track.

4. A method of determining the physical condition of a track, comprisingthe steps of l. continuously moving a vehicle on and along the track inthe direction of the track elongation;

2. subjecting the two rails of the track to horizontal loads from thecontinuously moving vehicle to press the rails in opposite lateraldirections and thus to produce a change in the shape or position of therails at the same point of the track; and

3. measuring the change in the shape or position of the rails producedby the horizontal loads,

a. the measured changes indicating the condition of the track.

5. A method of determining the physical condition of a track, comprisingthe steps of l. continuously moving a vehicle on and along the track inthe direction of the track elongation;

2. subjecting the track to mechanical forces from the continuouslymoving vehicle, said forces including causing at least one of the trackrails to vibrate; and

3. electroacoustically measuring the vibrations produced by saidmechanical forces,

a. the measured vibrations indicating the condition of the track.

6. A method of determining the physical condition of a track, comprisingthe steps of l. continuously moving a vehicle on. and along the track inthe direction of track elongation;

2. applying substantially constant mechanical forces to the track fromthe continuously moving vehicle,

a. the mechanical forces being sufficient to change the physicalcondition of the track at the points of application only while theforces are applied thereto;

3. measuring the changes in the track condition produced by the appliedmechanical forces at said points; and

4. producing signals corresponding to the measured changes to determinethe condition of the track over which the vehicle moves. 7. The methodof claim 6, wherein the mechanical forces Include pressure exerted upona selected part of the track to produce a change in the shape orposition of the selected track part.

d. The method of claim 6, wherein the mechanical forces include verticalloads imposed upon at least one of the track rails to produce a changein the shape or position of the rails.

9. The method of claim 6, wherein the mechanical forces includehorizontal loads imposed upon at least one of the track rails to producea change in the shape or position of the rails.

lit). The method of claim 6, wherein successive mechanical forces ofdifferent magnitudes are applied at the same point of the track from thecontinuously moving vehicle, each applied force corresponding to apredetermined norm causing a given change in the physical trackcondition of a normal track, whereby the measured changes indicatedeviations from the norm.

llll. The method of claim 6, wherein a constant mechanical force isapplied to a succession of points along the track from the continuouslymoving vehicle, the applied force corresponding to a predetermined normcausing a given change in the physical track condition of a normaltrack, whereby the measured changes indicate deviations from the norm.

12 The method of claim 6, wherein mechanical forces of differentmagnitude are applied from the continuously moving vehicle at points ofthe track spaced from each other in the direction of track elongation,the changes in the track condition produced at said points by thedifferent mechanical forces are measured, and the differences in thevalues of the mea sured changes are determined to indicate the conditionof the track over which the vehicle moves.

1. A method of determining the physical condition of a track, comprisingthe steps of
 1. continuously moving a vehicle on and along the track inthe direction of the track elongation;
 2. subjecting the track tosubstantially constant mechanical forces of different magnitude from thecontinuously moving vehicle at points of the track spaced from eachother in the direction of track elongation, the mechanical forces beingsufficient to change the physical condition of the track at the pointsof application only while the forces are applied thereto;
 3. measuringthe changes in the track condition produced at said points by thedifferent mechanical forces; and
 4. determining the differences in thevalues of the measured changes.
 2. subjecting the track to mechanicalforces from the continuously moving vehicle, said forces includingcausing at least one of the track rails to vibrate; and
 2. applyingsubstantially constant mechanical forces to the track from thecontinuously moving vehicle, a. the mechanical forces being sufficientto change the physical condition of the track at the points ofapplication only while the forces are applied thereto;
 2. subjecting thetrack to substantially constant mechanical forces of different magnitudefrom the continuously moving vehicle at points of the track spaced fromeach other in the direction of track elongation, the mechanical forcesbeing sufficient to change the physical condition of the track at thepoints of application only while the forces are applied thereto;
 2. Themethod of claim 1, wherein the track is simultaneously subjected to saidmechanical forces at said points.
 2. subjecting the track to successivesubstantially constant mechanical forces of different magnitudes at thesame point from the continuously moving vehicle, the mechanical forcesbeing sufficient to change the physical condition of the track at thepoints of application only while the forces are applied thereto; and 2.subjecting the two rails of the track to horizontal loads from thecontinuously moving vehicle to press the rails in opposite lateraldirections and thus to produce a change in the shape or position of therails at the same point of the track; and
 3. measuring the changes inthe track condition produced at each of said points by said mechanicalforces to indicate the condition of the track.
 3. A method ofdetermining the physical condition of a track, comprising the steps of3. measuring the changes in the track condition produced at said pointsby the different mechanical forces; and
 3. measuring the changes in thetrack condition produced by the applied mechanical forces at saidpoints; and
 3. electroacoustically measuring the vibrations produced bysaid mechanical forces, a. the measured vibrations indicating thecondition of the track.
 3. measuring the change in the shape or positionof the rails produced by the horizontal loads, a. the measured changesindicating the condition of the track.
 4. producing signalscorresponding to the measured changes to determine the condition of thetrack over which the vehicle moves.
 4. determining the differences inthe values of the measured changes.
 4. A method of determining thephysical condition of a track, comprising the steps of
 5. A method ofdetermining the physical condition of a track, comprising the steps of6. A method of determining the physical condition of a track, comprisingthe steps of
 7. The method of claim 6, wherein the mechanical forcesinclude pressure exerted upon a selected part of the track to produce achange in the shape or position of the selected track part.
 8. Themethod of claim 6, wherein the mechanical forces include vertical loadsimposed upon at least one of the track rails to produce a change in theshape or position of the rails.
 9. The method of claim 6, wherein themechanical forces include horizontal loads imposed upon at least one ofthe track rails to produce a change in the shape or position of therails.
 10. The method of claim 6, wherein successive mechanical forcesof different magnitudes are applied at the same point of the track fromthe continuously moving vehicle, each applied force corresponding to apredetermined norm causing a given change in the physical trackcondition of a normal track, whereby the measured changes indicatedeviations from the norm.
 11. The method of claim 6, wherein a constantmechanical force is applied to a succession of points along the trackfrom the continuously moving vehicle, the applied force corresponding toa predetermined norm causing a given change in the physical trackcondition of a normal track, whereby the measured changes indicatedeviations from the norm. 12 The method of claim 6, wherein mechanicalforces of different magnitude are applied from the continuously movingvehicle at points of the track spaced from each other in the directionof track elongation, the changes in the track condition produced at saidpoints by the different mechanical forces are measured, and thedifferences in the values of the measured changes are determined toindicate the condition of the track over which the vehicle moves.